Laser therapy for Bell's palsy: a systematic review and meta-analysis of randomized trials

This meta-analysis investigated therapeautic effects of laser therapies in patients with Bell's palsy (BP). The authors performed the literature search in the PubMed, Embase, and Cochrane Library databases using the following search terms: (facial paralysis OR Bell's palsy OR facial palsy OR idiopathic facial paralysis) AND (laser OR low-level laser OR photobiomodulation OR phototherapy). Relevant studies published before October 29th 2024 were identified. Randomized trials comparing the outcomes of laser therapies with other interventions, including electrical stimulation and control or usual care in patients with BP were included. The mean difference (MD) was determined as the effect size for continuous outcomes, and outcome accuracy was determined using 95% confidence intervals (CIs). Twelve studies were included, with a total of 597 patients. Nine studies were further included in the quantitative analysis. Our meta-analysis revealed that laser therapy significantly improved disease severity (House-Brackmann facial paralysis scale) (MD = -1.51, 95% CI = -2.43 to -0.59), facial asymmetry (Sunnybrook facial grading system) (MD = 20.63, 95% CI = 10.33 to 30.94), and facial function and disability (Facial disability index) (MD = 17.91, 95% CI = 5.60 to 30.22) when compared with control care in adult patients. Moreover, laser therapy significantly improved facial severity (MD = 21.05, 95% CI = 16.77 to 25.33) when compared with electrical stimulation. In addition, no adverse effects of laser therapy were reported. Laser therapy has favorable effects on disease severity, facial asymmetry, and facial function and disability for patients with BP.